1. Field of the Invention
The present invention relates to an image capture apparatus having a framing assistance zoom function and a control method therefor.
2. Description of the Related Art
Among image capture apparatuses such as digital cameras, there are image capture apparatuses having an optical magnification (optical zoom) function in which magnification is performed by driving a zoom lens and an electronic magnification (electronic zoom) function in which a portion of a region of a captured image is magnified. In recent years, because of an improvement of the performance of zoom lenses, image capture can be performed using the same lens for the variety of states from a super wide-angle state to a super telephoto state. Furthermore, because of an increase in the number of pixels included in an image capture element, even when the magnification for zooming-in is increased, image capture can be performed so that a satisfying feeling of resolution can be achieved.
A so-called preset zoom function and a shuttle shot zoom function are known as functions of moving, at a high speed, a zoom position to a position corresponding to an angle of view at which image capture is desired to be performed. The preset zoom function is a function in which, by operating a switch with a photographer, the zoom position is moved from any zoom position to a zoom position that is stored in advance in a memory. Furthermore, the shuttle shot zoom function is an extension function of the preset zoom function, and includes a return function of returning the zoom position to the original zoom position. In other words, the photographer operates a switch, whereby the zoom position is moved from any zoom position to the zoom position stored in the memory. In this case, the original zoom position is stored in the memory. When a preset zoom operation finishes, the zoom position can be returned to the original zoom position.
In Japanese Patent Laid-Open No. 2006-50019, a control apparatus having the preset zoom function and the shuttle shot zoom function is disclosed. In this control apparatus, a memory zoom operation of changing from a first zoom state to a second zoom state can be performed. The first zoom state is a state in which the zoom position is located in one of an optical zoom region and an electronic zoom region, and the second zoom state is a state in which the zoom position is located in the other zoom region and which is stored in a storage unit. Furthermore, in an apparatus disclosed in Japanese Patent Laid-Open No. 2001-117153, a manual operation member that is used to select a storage operation or a reproduction operation is provided. The storage operation is an operation in which a zoom position is stored using the preset zoom function, and the reproduction operation is an operation of returning to the stored zoom position. The manual operation member can be operated by a finger different from a finger by which another manual operation member that is used to perform the operation selected by the manual operation member is operated.
Regarding image capture apparatuses having a zoom function with a super high magnification, in the case where such an image capture apparatus is in the super telephoto state and the angle of view is adjusted, even slight movement of a subject may cause the subject to go out of a frame. Furthermore, even a panning operation that is performed in a moment by a photographer who holds a camera leads to a large change in the range of the angle of view. As described above, in the case of the super telephoto state, there is an issue that it is difficult to perform framing so that a subject which is a moving body is placed within a frame at a desired angle of view.
In the case where the preset zoom function or the shuttle shot zoom function disclosed in Japanese Patent Laid-Open No. 2006-50019 and Japanese Patent Laid-Open No. 2001-117153 is used, after a photographer performs a manual operation of moving, once, the zoom position to a zoom position at which the photographer desires to perform image capture, the zoom position needs to be stored in a memory. For this reason, in the case where a moving subject that has gone out of a frame is followed and an image of the subject is captured or in the case where the size of an image of a subject has been changed, it takes time to update the details of the stored zoom position. Accordingly, the photographer may miss a shutter release opportunity. Moreover, in the related art disclosed in Japanese Patent Laid-Open No. 2001-117153, in order to capture an image of a subject so that the subject has a predetermined size in the captured image while following the subject which has gone out of a frame, the photographer needs to become familiar with a manual operation procedure. The reason for this is that it is necessary to store the zoom position while repeating a manual zoom operation using multiple manual operation members.